[LUCENE-4940] ToParentBlockJoinQuery throws exception on empty parent filter DocIdSet

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.3, 6.0
• Fix Version/s: 4.3, 6.0
• Component/s: modules/join
• Lucene Fields: New, Patch Available
• Assignee: Simon Willnauer
• Reporter: Simon Willnauer
• Created: 18/Apr/13 07:30
• Updated: 28/Aug/22 13:44
• Resolved: 18/Apr/13 08:11

Description

previously DocIdSet.EMPTY_DOCIDSET retuned NO_MORE_DOCS by default when DocIdSetIterator#docId() was called but since LUCENE-4924 we return -1 if the empty iterator is unpositioned / not exhausted. This causes an IllegalStateException since we couldn't detect the empty DocIdSet. Our tests somehow don't catch this and I ran into it integrating my RC0 that I build into ES last night so this is unreleased...